装载机后车架失效原因分析

新设计的某型号装载机后车架,在做台架试验过程中出现了断裂,针对这一情况,用美国大型有限元分析软件NASTRAN对该结构进行了强度分析.阐述了用有限元法对后车架进行强度分析的建模过程,并对分析结果进行了分析.结果表明,由于后车架设计存在缺陷,从而导致某应力集中处应力过高,而且应力过高点是在焊缝部位,这就更加增大了断裂的可能性,说明后车架存在设计缺陷是导致其断裂的主要原因.针对这一情况,设计了一种新型结构,新结构一方面避免了在关键部位存在焊缝,同时降低了最大应力值.经再一次分析表明,新结构强度比原结构有了很大提高,理论上满足设计要求.在其投入市场以来,新型后车架并未发生断裂现象,从而表明查找出的断裂原因正确,对原结构的修改合理.时也表明所建立的有限元模型适用,分析结果可靠.

Cause Analysis for Rear Frame Failure of a Loader

A crack occurred on rear frame during bench test of a newly de- veloped loader.Aiming at the situation,strength analysis is con- ducted on the structure with large scale finite element analysis software NASTRAN.Its modeling procedure during strength anal- ysis with finite element method is described and the results are analyzed.The results show that:there is a defect in the rear frame design and it results in over-high stresses at stress concentrated area;moreover,the over-high stress area is in welds,which...